Arthur Jones knows exactly why his brother, Jon, didn’t take a fight with Chael Sonnen on short notice earlier this month. It’s all about his legacy, said Arthur, who plays defensive end for the Ravens.

“He wants to be known as one of the greatest fighters of all time,” Arthur told The Post. “He wants to be the Michael Jordan of the UFC, not just about fighter that had the potential to be great.”

Arthur said Jon “made the right decision” to refuse the fight with Sonnen. Jon, the light heavyweight champion, was supposed to face Dan Henderson on Sept. 1 at UFC 151. Henderson got hurt, pulled out and the UFC offered Jon a matchup with Sonnen, an exceptional trash talker, but someone who has fought at middleweight his entire UFC career. Jon turned it down and the UFC ended up canceling the entire card since it had no main event.

“Why give a guy a shot that’s been losing?” Arthur said. “It’s a title shot. If Jon had a month and knew his opponent, Jon would have took that fight no problem.”

Arthur said he wasn’t surprised that fans turned against Jon in the UFC 151 aftermath.

“I call them Twitter gangsters,” Arthur said. “Guys who talk all the junk in the world on Twitter and these are the same people asking for autographs when they see you in person.”

However, he said he was surprised that UFC president Dana White “threw [Jon] under the bus.” In a media conference call about the event cancellation, White ripped Jon and his coach Greg Jackson for not taking the fight.

“There are so many more questions to ask – like why was that card so weak that it had to be cancelled?” Arthur said. “These fighters are not puppets. They’re humans, too. It sucks that there’s no union or anything. It shows how the UFC is different from the NFL.”

Arthur trains in MMA in the offseason and says he “loves the sport a lot.” He said it helps his cardio and how to understand his body more. As for possibly fighting sometime down the line, Arthur left the door open.

“I’ve thought about it, but right now I’m focused on football,” he said. “We’ll see for the future.”